Tanning process



- slips.

7 UNITED STATES- PATENT FIcE.

JOHN HENRY, JAMnsyor AS VI LE, ARKANSAS, AsSIcNoRfoF F E- EIGHTHS, BY DIRECT AND MESNE ASSIGNMENTS, TO wILLIAMr. ROBERTS, JR, AND FRANK D. THOMASON, or CHICAGO, ILLINOIS.

TANNING-PROCESS,

SPECIFICATION forming part 66 Letters Patent Nb. 506,696, dated Octobertlr', 1893.

Application filed January l8 1892. Serialllo. 418,420. (No specimens.)

To all whom it may concern.-

Be it known that I. J OHN'HENRY :J AMES, a citizen of the United States, residing at'Nashville, in the county of Howard and State of Arkansas, have invented a new and useful Tanning Process, of which the following is a specification.

This invention relates to processes for tanning hides and compositions of matter used in connection therewith, especially for man ufacturing sole, harness or upper leather; and it has for its object to provide an improved process and compound whereby the resultant leather after being subjected to the treatment embraced in this invention, will be soft and pliable, yet possessing a good body and color and having the characteristics of all good grades of leather.

With these and many other objects in view which will readily appear to those skilled in the art as the nature of the invention is better understood, the same consists in the various steps and solutions used in connection therewith as will be hereinafter set forth and claimed.

Before subjecting the hides to the tanning process proper, the same are subjected to several preliminary steps which particularly fit the same for being rapidly and efiectively acted upon by the tanning solution and process. After thoroughly soaking the green or dry hides in clear water and removing the flesh therefrom,the same are placed in aliming vat containing suitable proportions of lime, lye soap or laundry soap. The hides remain immersed in this liming vat, being occasionally aired at suitable intervals, until the hair The hides are now thrown into clear water and the hair worked out on the beam. Then the same are skived and flattened out as evenly as possible. From the liming vat, the hides are next thrown into a bate pool containing one thousand gallons of water, and one half bushel of corn meal or one bushel of wheat bran previously prepared by perfect fermentation. The bate pool solution is kept at a temperature of about 80 and frequently stirred. After remaining only for quite a short period in the bate pool, the hides are removed, and all the remaining lime and short hair taken therefrom and then washed. 1 With these preliminaries the hides the tanning process.

The first tanning mixture which receives the hides is composed of twenty pounds" of Glaubers salts, twenty-two poundsof alum; twenty-five pounds of saltpeter, forty pounds of salt, and fifty pounds of gambier, which ingredients arethoroughly dissolved and added in solution to eight hundred gallons'of clear water. The hides are placed inthis solution and for the first few days are handled every few hours. Thereafter from every six to twelve hours and continued until the hides are thoroughly tanned into leather. Having subjected the hides to this tanning process proper the same are now again returned to the aforementioned solution to which has been added one hundred pounds of bark extract. The solution is then heated to blood heat, and the hides therein are handled for forty-eight hours, at which time the leather will have a good body and color. The same is now tobe well scoured, set, stufied thoroughly, and finally allowed to dry. The leather thus produced possesses all the essential qualities of and is particularly adapted for use as sole, harness or upper leather as originally premised.

A fact of importance not to be overlooked in connection with the improvements herein set forth, is that the bark extract is added to the coldsolution of the tanning mixture before heat is applied with the hidesimmersed in such solution, and by practical experiment it has been found that in order to secure the proper results the addition of .the bark extract at this stage, and the heating up of the solution after the addition thereof, is absolutely necessary to secure the results claimed. It is to be understood that the addition of the bark extract at this stage of the process not only serves to strengthen up the solution but also improves the color and renders a better quality of leather, and it has been found that after the hides have been subjected to the action of the tanning mixture without the bark extract, the gelatine or glue in'the hides is in the proper condition to receive the action of the tonic acid or bark extract, which toare ready for t gether with the mixture to which it is added, being heated up to ablood heat, makes the leather sti E, hard and impervious to the water, without breaking or cracking, which invariably occurs in processes wherethe leather is hardened up by introducing and applying hot ooze or liquor at any stage of the tanning, in-

asmuch as the combination of a warm or hot provement which consists in primarily depilating and hating, subjecting to the tanning action of a tanning mixture composed of Glaubers salts, alum, saltpeter, salt and gambier, introducing into such tanning mixture a proportionate quantity of bark extract, while such tanning mixture is in a cool condition, re-immersing the hides in the new solution, raising the temperature of the latter wit-h the hides therein to a blood heat, and handling and manipulating the hides at intervals in the heated solution, substantially as set forth.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

JOHN HENRY JAMES.

Witnesses: r J AS. P. NEILLIVER, N.. E. MULKEY. 

